I am in the habit of leaving the label or part of it on sheets of conditioned clay, especially for a clay that I have not used before. I usually use Fimo and have had no problem with this practice. When I tried this trick with Premo the ink on the package label smudged. This seems to be old packaging, perhaps the newer packaging will not so this. The printed surface of the packaging was not in direct contact with the clay but the ink dissolved. I will continue to observe.